Engineering projects that require maintainable code should always start with a team of 3 or more engineers. Why such an arbitrary number, you might ask? Why can’t a single engineer write maintainable code? Perhaps your thoughts might lean towards peer-review for PRs and arrive at the number 2. Two engineers should be enough to properly review. So why is it important for software to be maintainable? Software in the real world is only written to solve a problem for someone.

How should software be built? It depends. There isn’t a single “correct” way to build software. An early stage startup might focus on speed over maintainability, because they’re looking to find Product-Market Fit (PMF). A scale-up which has found PMF might focus instead on maintaining engineering velocity. Both are solutions to two completely different equations. If we broadly group development “modes” into two buckets we can come up with the following buckets: